Shielding type medium-voltage insulation power cable

Abstract

The utility model discloses a shielding type medium-voltage insulation power cable which comprises a cable core. The cable core is composed of two groups of mutually twisted wire cores, each group of wire core is composed of a conductor, a conductor shielding layer and a conductor insulating layer, the cable core is wrapped by an insulation shielding layer, the insulation shielding layer is composed of a semi-conductive layer, a reinforcing layer and a protective layer, the insulation shielding layer is externally provided with a metal shielding layer, and the metal shielding layer is externally provided with a shielding layer. The metal shielding layer is composed of an anti-interference layer, an alloy layer and a braid layer. According to the scheme, the problem that the shielding effect of the power cable is poor is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of power cables, in particular to a shielded medium-voltage insulated power cable. Background Art

[0002] Medium voltage insulated power cable is a conductor specially designed for transmitting medium voltage electricity and energy. It plays a vital role in the power system. Medium voltage cable usually refers to cables with a rated voltage between 1kV and 35kV. These cables are mainly used in distribution grids, urban power supply and power transmission and distribution systems in power systems. Medium voltage cables use special insulation materials and structural design to withstand power transmission and work in high temperature environments. They can generally work for a long time in high temperature environments of 70℃ to 150℃.

[0003] For example, the Chinese authorized patent with announcement number CN214588181U is a medium-voltage insulated power cable, including a central air pipe, on the outer pipe wall of the central air pipe, a number of insulating sleeves are fixedly connected in an annular manner at uniform intervals, a cable core conductor is arranged in the insulating sleeve, an anti-interference shielding layer is fixedly sleeved on the outer arc-shaped side walls of the several insulating sleeves, an inner sheath is fixedly sleeved on the outer annular side wall of the anti-interference shielding layer, a number of buffer strips are fixedly connected in an annular manner at uniform intervals on the outer annular side wall of the inner sheath, a cylindrical buffer air cavity is opened in the buffer strip, and an outer sheath is fixedly sleeved on the outer arc-shaped side walls of the several buffer strips.

[0004] When the above-mentioned existing technology is actually used, the current in the cable and the current in the surrounding wires may affect each other, resulting in current waveform distortion and nonlinear changes in voltage, thereby interfering with the original normal current waveform and voltage stability in the cable. Therefore, it does not meet the existing needs. In this regard, we propose a shielded medium-voltage insulated power cable. Utility Model Content

[0005] The purpose of the utility model is to provide a shielded medium-voltage insulated power cable to solve the problem of poor shielding effect of the power cable proposed in the above background technology.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a shielded medium-voltage insulated power cable, comprising a cable core; the cable core is composed of two groups of twisted cores, each group of cores is composed of a conductor, a conductor shielding layer and a conductor insulation layer, the outside of the cable core is wrapped with an insulating shielding layer, the insulating shielding layer is composed of a semi-conductive layer, a reinforcing layer and a protective layer, a metal shielding layer is arranged on the outside of the insulating shielding layer, and the metal shielding layer is composed of an anti-interference layer, an alloy layer and a braided layer.

[0007] Preferably, the conductor is formed by twisting a plurality of aluminum alloy monofilaments into a bundle, the conductor shielding layer is extruded on the outer wall of the conductor, and the conductor insulating layer is extruded on the outer wall of the conductor shielding layer.

[0008] Preferably, the semiconductive layer is wrapped around the outside of the cable core by an extrusion device, the reinforcement layer is fixed to the outer wall of the semiconductive layer by a polymer adhesive, and the protective layer is wrapped around the outer wall of the reinforcement layer by an extrusion device.

[0009] Preferably, the anti-interference layer is spirally wound on the outside of the insulating shielding layer, the alloy layer is spirally wound on the outer wall of the anti-interference layer, and the braided layer is mesh-wrapped on the outer wall of the alloy layer.

[0010] Preferably, a filling layer is provided at the gap between the cable core and the wire core, and the filling layer is made of carbon black powder.

[0011] Preferably, an outer sheath is provided on the outside of the metal shielding layer, and the outer sheath is fixed to the metal shielding layer by an extrusion process.

[0012] Preferably, the insulating shielding layer and the metal shielding layer have the same thickness.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. The utility model is provided with an insulating shielding layer. Through the optimized design of the multi-layer structure, the composite insulating shielding layer can more effectively improve the electric field distribution of the cable, reduce the partial discharge phenomenon, and improve the electrical performance and safety of the cable. Through the optimized design of the multi-layer structure, the composite insulating shielding layer can more effectively improve the electric field distribution of the cable, reduce the partial discharge phenomenon, and improve the electrical performance and safety of the cable. The design of the multi-layer structure makes the composite insulating shielding layer have better mechanical strength and stress resistance, and can withstand greater external impact and bending deformation.

[0015] 2. The utility model is provided with a metal shielding layer. The composite metal shielding layer can provide an all-round, multi-level electromagnetic shielding effect, effectively suppressing the influence of external electromagnetic interference on the internal signal of the cable. The combination of the inner copper tape, the middle corrosion-resistant alloy layer and the outer high-strength braided mesh makes the overall metal shielding layer have extremely high mechanical strength and can withstand greater external pressure and impact. The corrosion-resistant alloy layer in the middle layer can resist chemical corrosion and oxidation in various harsh environments, ensuring the stability and reliability of the cable during long-term use.

[0016] 3. The spirally wound design of the two cores in this utility model enables the cable to carry greater current with the same outer diameter. The close contact and mutual support between the conductors enhances the cable's mechanical properties and stress resistance, allowing for a higher current carrying capacity. Although the carbon black filling the gaps does not directly constitute an insulating layer, it works together with the insulation layer to improve the cable's overall insulation performance. The carbon black's conductivity helps provide a degree of short-circuit protection when the insulation layer is damaged, reducing the risk of electrical accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional diagram of the utility model;

[0018] Figure 2 It is a cross-sectional structural diagram of the utility model;

[0019] Figure 3 This is a schematic diagram of the insulation shielding layer structure of the utility model;

[0020] Figure 4 This is a schematic diagram of the metal shielding layer structure of the present utility model.

[0021] In the figure: 1. Wire core; 11. Conductor; 12. Conductor shielding layer; 13. Conductor insulation layer; 2. Insulation shielding layer; 21. Semi-conductive layer; 22. Reinforcement layer; 23. Protective layer; 3. Metal shielding layer; 31. Anti-interference layer; 32. Alloy layer; 33. Braided layer; 4. Outer sheath; 5. Filling layer. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0023] See also Figure 1-4 The utility model provides an embodiment: a shielded medium-voltage insulated power cable, comprising a cable core; the cable core is composed of two groups of mutually twisted cores (1), each group of the cores 1 is composed of a conductor 11, a conductor shielding layer 12 and a conductor insulating layer 13, the outside of the cable core is wrapped with an insulating shielding layer 2, the insulating shielding layer 2 is composed of a semi-conductive layer 21, a reinforcing layer 22 and a protective layer 23, the outside of the insulating shielding layer 2 is provided with a metal shielding layer 3, the metal shielding layer 3 is composed of an anti-interference layer 31, an alloy layer 32 and a braided layer 33, and the thickness of the insulating shielding layer 2 and the metal shielding layer 3 are equal.

[0024] See also Figure 2The conductor 11 is made of multiple aluminum alloy monofilaments twisted together into a bundle. The conductor shield 12 is extruded onto the outer surface of the conductor 11, and the conductor insulation 13 is extruded onto the outer surface of the conductor shield 12. The conductor 11 is made of aluminum alloy monofilament to reduce resistance and improve power transmission efficiency. The multiple filaments are twisted into a bundle and compressed using a special mold to increase the compression coefficient, thereby enhancing the cable's mechanical properties and current carrying capacity. The conductor shield 12 is made of semi-conductive rubber, which has excellent conductivity and flexibility, making it ideal for the semi-conductive layer of the cable. It can effectively improve the cable's electric field distribution, reduce partial discharge, and enhance the cable's electrical performance and safety. The insulation 13 is made of cross-linked polyethylene to improve dielectric strength, heat resistance, and mechanical properties.

[0025] See also Figure 3 The semiconductive layer 21 is wrapped around the cable core using an extrusion machine. The reinforcement layer 22 is fixed to the outer surface of the semiconductive layer 21 using a polymer adhesive. The protective layer 23 is also wrapped around the outer surface of the reinforcement layer 22 using an extrusion machine. The semiconductive layer 21 is made of silicone rubber, which has high conductivity and can tightly adhere to the conductor surface, forming a smooth equipotential layer. This effectively eliminates charge accumulation on the conductor surface, improves the electric field distribution, and reduces partial discharge. The introduction of nanomaterials also enhances the material's conductivity and mechanical strength. The reinforcement layer 22 is made of nano-alumina, which not only has excellent insulation properties but also improves its heat resistance, mechanical strength, and aging resistance through the reinforcement effect of nanoparticles. It can withstand higher temperatures and greater mechanical stress, extending the cable's service life. The protective layer 23 is made of a thermoplastic elastomer, which has excellent flexibility and elasticity. It can tightly adhere to the other layers of the cable and provide additional mechanical protection. Its semiconductive properties also help further balance the electric field distribution within the cable, improving electrical safety.

[0026] See also Figure 4 The anti-interference layer 31 is spirally wound around the outside of the insulating shielding layer 2, the alloy layer 32 is spirally wound around the outer wall of the anti-interference layer 31, and the braided layer 33 is mesh-wrapped around the outer wall of the alloy layer 32. The anti-interference layer 31 is an electrolytic copper tape, which can effectively transmit current and shield electromagnetic interference, providing a reliable grounding path for the cable; the alloy layer 32 is a nickel alloy, which can resist chemical corrosion and oxidation in the external environment, protect the inner copper tape from damage, and extend the service life of the cable. At the same time, alloy materials generally have high mechanical strength, which can enhance the compression and bending resistance of the overall metal shielding layer; the braided layer 33 is woven from aluminum-magnesium alloy wire, which not only has extremely high mechanical strength and can withstand external physical impact and extrusion, but also provides a wider range of electromagnetic shielding effects through a dense woven mesh. In addition, the design of the braided mesh also has good flexibility and workability, which facilitates the bending, installation and maintenance of the cable.

[0027] See also Figure 2The gap between the cable core and the wire core 1 is filled with a filling layer 5. This filling layer 5 is made of carbon black powder, which has the characteristics of highly crystalline carbon and good conductivity. In cable manufacturing, carbon black is often used as a conductive filler, added to polymer materials to improve their conductivity. This composite material with added carbon black is often used to make the semi-conductive layer of the cable.

[0028] See also Figure 1 and Figure 2 An outer sheath 4 is provided on the outside of the metal shielding layer 3, and the outer sheath 4 is fixed to the metal shielding layer 3 by an extrusion process. The outer sheath 4 is made of flame-retardant, cold-resistant and heat-resistant polyvinyl chloride. The PVC sheath material has good flexibility and firmness, can protect cables or wires from external physical damage, and has certain fire and oil resistance. Although PVC is not completely flame retardant, it can slow down the spread of fire under certain conditions and can resist the erosion of oil substances to a certain extent.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A shielded medium voltage insulated power cable comprising a cable core; characterized in that: The cable core is composed of two groups of twisted cores (1), each group of cores (1) is composed of a conductor (11), a conductor shielding layer (12) and a conductor insulation layer (13), the outside of the cable core is wrapped with an insulation shielding layer (2), the insulation shielding layer (2) is composed of a semi-conductive layer (21), a reinforcement layer (22) and a protective layer (23), and a metal shielding layer (3) is provided outside the insulation shielding layer (2), the metal shielding layer (3) is composed of an anti-interference layer (31), an alloy layer (32) and a braided layer (33).

2. A shielded medium voltage insulated power cable according to claim 1, characterized in that: The conductor (11) is formed by twisting a plurality of aluminum alloy monofilaments into a bundle, the conductor shielding layer (12) is extruded on the outer wall of the conductor (11), and the conductor insulating layer (13) is extruded on the outer wall of the conductor shielding layer (12).

3. A shielded medium voltage insulated power cable according to claim 1, characterized in that: The semiconductive layer (21) is wrapped around the outside of the cable core by an extrusion device, the reinforcement layer (22) is fixed on the outer wall of the semiconductive layer (21) by a polymer adhesive, and the protective layer (23) is wrapped around the outer wall of the reinforcement layer (22) by an extrusion device.

4. A shielded medium voltage insulated power cable according to claim 1, characterized in that: The anti-interference layer (31) is spirally wound on the outside of the insulating shielding layer (2), the alloy layer (32) is spirally wound on the outer wall of the anti-interference layer (31), and the braided layer (33) is mesh-wrapped on the outer wall of the alloy layer (32).

5. The shielded medium voltage insulated power cable according to claim 1, characterized in that: A filling layer (5) is provided at the gap between the cable core and the wire core (1), and the filling layer (5) is made of carbon black powder.

6. The shielded medium voltage insulated power cable according to claim 1, characterized in that: An outer sheath (4) is provided on the outside of the metal shielding layer (3), and the outer sheath (4) is fixed to the metal shielding layer (3) using an extrusion process.

7. The shielded medium voltage insulated power cable according to claim 1, characterized in that: The insulating shielding layer (2) and the metal shielding layer (3) have the same thickness.

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